Merit award — Companies and organisations with the most improved environmental practice: Sasol One waste site remediation project
The overhaul of waste disposal and storage processes at the Sasol One waste site has had significant environmental and some financial benefits.
The Sasol One site began operating in 1956 and the waste produced was disposed at an on-site facility. In the 1990s Sasol started formal investigations to classify its waste streams.
Four basic principles of waste management were applied: waste avoidance at source, waste treatment, waste disposal and waste recycling. By introducing cleaner technologies with this waste classification process, significant reductions in waste volumes were achieved.
The coal gasification process was replaced with a cleaner feed stream process, using natural gas.
“The single biggest change in the reduction of waste volumes was seen when the gasification process was stopped,” said Sasol’s principal environmental specialist, Johann van Wyk.
“The process change to natural gas made huge environmental improvements,” said Van Wyk. “The improvements were seen in a reduction in water usage, waste volumes, as well as emissions to the atmosphere.”
Waste disposal volumes dropped significantly from 21 372 tonnes in 2004 to 6 468 tonnes in 2007.
Following integrated waste management principles that focus on environmental impacts associated with the disposal of waste, including historical waste streams, Sasol conducted a number of studies.
“The studies indicated that groundwater impacts occurred due to the waste disposal activities,” said Van Wyk. “The impacts were, however, manageable and intervention would see an improvement in groundwater qualities.”
A number of remediation measures were laid out with time frames and agreed upon in consultation with the department of water affairs and forestry. These included reshaping the dry dump so that an engineered capping system could be placed over it, preventing surface water from entering the body of waste and leaching into the groundwater.
The Omnia and Fisions waste facilities, where fertiliser waste was disposed, was identified as having an impact on surface and sub-surface water.
Van Wyk said the two dumps were consolidated to reduce their footprint and a capping system was introduced to prevent water entering into the waste body.
The ash in the coarse was mined and the ash was sold to brick makers, while some of the ash was used to stabilise tar and oil wastes.
An average of 120 000 tonnes of ash is sold to brick makers on a monthly basis, Van Wyk said. Which goes to show that when companies think constructively about their waste management processes, sometimes there are economic incentives that have not been anticipated.
The Greening the Future judges praised this project for its genuine motivation and the recognition that industrial waste cannot be treated as business as usual. They noted that the on-site remediation went beyond legal compliance.